Masked photographic product for receiving a transfer image



H. MASKED PHOTOGRAPHIC PRODUCT FOR May 11, 1954 G. ROGERS RECEIVING A TRANSFER IMAGE Filed Feb. 19, 1949 lNvEA-ion WNV@ m Patented May l1, 1.95.4

MASKED PHOTOGRAPHIC PRODUCT FOR RECEIVING A TRANSFER IMAGE Howard G. Rogers, Weston, Mass., assignor to Polaroid Corporation, Cambridge, Mass., a corporation of Delaware Application February 19, 1949, vSerial No. 77,362

2 Claims.

This invention relates to photography and more particularly to improvements in photographic products of the type adapted for the production of a positive image under the selective control of the development of a negative image .in a photosensitive silver halide layer which may ,'.be a part of the product. In general, the product of this invention is particularly adapted for, although not limited to, use in a camera of the Atype shown in U. S. Patent No. 2,455,111 of November l0, 1948, to Carbone and Fairbank, a preferred type of such a camera having a back ldoor through which the positive image is removed.

A principal object of the present invention is to provide means for framing the positive image which is an improvement over the means shown :in the copending application of Howard G. Rogers and William J. McCune, Jr., Serial No. l6,058, filed February 3, 1948 (now Patent No. 2,659,673, issued November 17, 1953).

Another object of the invention is to provide .'such yframing means in the form of a mask securedl to the surface of an image-carrying layer :which can be rolled into a small roll without fdanger of separating from the surfa-ce of the image-carrying layer during formation of the roll or-during the unrolling thereof when the positive image is to be formed.

Still another object of the invention is to pro- 'vide such a framing mask which will not become inadvertently detached from the image-carrying 'layer during storage of the resultant product :under Widely varying conditions of temperature :and humidity.

Still another object of the invention is to pro- 'vide such a mask which may be predeterminedly :secured to the image-carrying layer by means of 4`two layers of organic-solvent-spluble plastics which define a line of cleavage therebetween.

' These and other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the product possessing the features, properties and the relation of components, which are exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawing wherein:

l Figure l is a diagrammatic view of one preferred form of the invention during the use thereof, With parts cut away for clarity of illustration;

Fig. 2 is a diagrammatic, exaggerated, greatly enlarged, fragmentary, sectional view of the product of Fig. 1, taken along the line 2-2 of Fig. l, but with the elements superposed in processing relationship to the photosensitive layer; and

Fig. 3 is a fragmentary, sectional view similar to Fig. 2 showing the relationship of the elements when the image area is being separated from the image-carrying layer.

In general, the present invention relates to improved fra-ming means for a positive image-carrying layer adapted to be brought into superposed relation with an exposed silver halide photosensitive layer and processed by spreading between the superposed layers a viscous liquid capable of developing a latent negative image in the photosensitive layer and forming a positive image thereof on the surface of the image-carrying layer. In the above-mentioned copending application, the preferred framing means comprises a thin paper mask or frame which has a cut-out portion dening an image area on the surface of the image-carrying layer. This frame is temporarily bonded to the surface of the imagecarrying layer, preferably by the use of two layers ofplastic between the thin paper mask and the image-carrying layer, these plastic layers being suchthat they have a greater ainity for their adjacent sheets than they have for each other. When the image area portion of the image-carrying layer is separated from the remainder thereof, the two plastic layers dene a ready line of cleavage therebetween. When a mask of the above type becomes inadvertently separated from the borders of the picture area it permits separation of the photosensitive and image-carrying layers at these places and spoils the image along these borders.

If a composite structure, comprising a. mask sheet superposed on an image-carrying layer, is formed into a roll by rolling said structure upon litself so that the mask is innermost, the mask is compressed or shortened to a length which is less than its length in a flat condition. When the unit is unrolled, the mask sheet will lengthen out to its unrolled length. This compression or shortening upon rolling a mask sheet which is bonded to an image-carrying layer creates a shearing force tending to disrupt the adhesive bond between the mask sheet and the image-carrying layer. A similar condition occurs when the mask is unrolled. Likewise, buckling ripples Which may occur during rolling-'tend to separate the mask shortened by an amount which is preferably.

greater than the maximum elongation to which the mask wouldbe subjected during normal storage or use. The shortening process is preferably accomplished by relatively permanently deforming the mask from its normal plane at a number of closely spaced points. In order to retain the flexibility of the mask, this deformation is preferably accomplished by crimping the mask, this crimping preferably comprising a waveshaped crimp, the axis of the waves being parallelto the axisof the roll into which the mask is to be formed. This crimping thus gives considerable lexibility to the mask with respect to any bending or buckling force applied around an axis parallel to the roll axis.

Thecrimped mask is then heat-sealed to the reated surface of the image-carrying layer, this heat-sealing being preferably accomplished under pressure which is applied to a relatively large area ofthe mask to prevent any substantial elongation of the mask during the heat-sealing. This pressure is preferably quite high so that it mashes the crimped `mask down sufficiently so that the mask-surface substantially smooth, there being only slight creases showing in this surface. This heat-sealing under the high pressure also appears to ycompress the bers of the mask so that it does not substantially lose its ability to stretch. The troughs or low points of the crimp waves are in Contact with the image-carrying layer when the mask is seated thereon prior to applying laminating pressure thereto. Crimp waves of the mask arepartially flattened out by the laminating pressure `whereby much of the material initially out of contact with the image-carrying layer is pressed into contact therewith. Bonding of the mask sheet to the image-.carrying layer is effected at substantially all portions thereof brought into contact ywith the image-carrying layer and subjected to said laminating pressure.

When such a mask is formed into a roll Whose inner diameters-is, for example, approximately of an inch and is then unrolled, the percentage compression during rolling, and the percentage elongation during unrolling, of the mask will be a function `of the thickness of the various layers thereof." When the image-carrying layer is .006 inch thick, the mask is .0018 inch thick and the plastic is about .0006 inch thick,` the innermost mask of the roll will be subjected to a compression of about .8% in length when the composite sheet is rolled into a 3A inch roll. When such a roll is stored for a long period of time, particularly under low humidity conditions, the compressed mask assumes the shortened length it has in the roll. When the composite sheet is again unrolled to a flat condition the mask is subjectedA to an elongation of approximately .8%. When the mask is shortened, by the crimping operation, by approximately 2%, and most of this shortening is left-after heat-sealing, there is adequate compressibility and stretch in the mask to permit the mask to be compressed and stretched this .8% during the rolling and unrolling thereof, even though the mask is sealed to the image-carrying layer. Consequently, when the composite sheet is unrolled, there is no tendency for the imagecarrying layer to shear the heat-seal bond between the mask and the image-carrying layer, as would be the case if the mask did not stretch. This stretchability of mask also the very important advantage of making feasible the use of a bond between the two plastic layers that is weaker than would be possible if the mask were not able to stretch. This is due to the fact that the force necessary to shear the bond between the plastic layers is much greater along the layers than normal thereto. The stretchability of the mask tends to keep this shear force along the bond rather than no1-mal thereto. This weaker bond naturallymakes the removal of the image area much simpler and avoids any possibility of tearing the edges of the image area.

Where the mask and image-carrying layer are bent sharply in the same direction as the roll, but around a radius smaller than the initial roll, any buckling which might take place in the mask, due to the shorteningthereof, is not transmitted along the mask due to the ilexibility of the mask with respect to a bending force applied around an axis parallel to the roll axis. Additionally, the crimping of the mask seems to permit almost any amount of shortening thereof, which might be necessary to accommodate any bending of the image-carrying layer, without causing any buckling of themask.

Referring now to the various gures, the present invention is shown in the operative relationship the element thereof will assume when used in a processing camera of the type illustrated' in the above-mentioned Carbone and Fairbank patent. In the various gures, IU `:represents a sheet of photosensitive nlm, having a silver halide emulsion l l coated thereon, while l2 is the imagecarrying layer. The mask, shown at i4, is indicated in a preferred form as being slightly narrower than the image-,carrying layer I2 and as having a number of cutaway portions l5 roughly corresponding to image area portions I8 on the image-carryinglayer l2. These image area portions I are preferably defined by perforations 'surrounding each ofthe image area portions. The mask i4 is shown as preferably covering these perforations 2l! so as to prevent the processing liquid from passing through these perforations and also to give a border toA the positive image formed on the image area portion I8. A predetermined small quantity of a processing liquid 2l is carried by each of a plurality of containers 22, each of the containers having a liquidreleasing mouth 2&5 adjacent one edge of the adjacent edge of an image area portion I8. The container 22 is preferably secured to the mask i4, such as by means of a cellulosic tape 26 having a pressure-sensitive adhesive c-oating. A pair of trap elements 28-is operatively associated with each container for trapping excess liquid spread from its operatively associated container. Each pair of trap elements is positioned adjacent the opposite edge ofthe image area portion lfrom its operatively associated -container so as to trap excess liquid spread from the container, across the image area andtowards the trap elements.

Referring now more particularly to Figs. 2 and 3, there are shown greatly enlarged fragmentary sectional views of the mask and image-carrying layer. As seen best in these enlarged views, the mask ifi is secured to the image-carrying layer by lmeans of two layers of plastic 3l? and 32. It can also be seen that the right-hand portion of the mask, in Figs. 2 and 3, adjacent a rtear out sheet of baryta paper treated in accordance with the teachings set forth in the above mentioned copending application. The mask I4 preferably comprises a sheet of sulphate kraft condenser tissue paper approximately .0018 inch thick. The two plastic layers 30 and 32 may comprise, respectively, polyvinyl alcohol and ethyl cellulose. In apreferred form of the invention, the plastic layers 30 and 32 are coated on the mask in accordance with the following nonlimiting example:

EXAMPLE A mixture is prepared by mixing, by volume, one part methanol, three parts ethyl acetate and four parts of methyl Cellosolve. To 100 cc. of this mixture there are added 5 grams of cellulose acetate flake. The resulting solution is coated on the mask paper by use of a suitable doctor blade and roller to give a dry layer 30 having a thickness of approximately .0002 inch. The ethyl cellulose layer 32 is then similarly applied by use of a solution containing 80 grams of ethyl cellulose, 13 cc. of diethyl phthalate, 320 cc. of toluene and 80 cc. of denatured alcohol. The ethyl cellulose coating is applied over the cellulose acetate to give a dry coating which is preferably .0001 inch thick.

After the double layer coating has dried, the mask is relatively permanently shortened, preferably by crimping the mask. This crimping is preferably accomplished by passing the coated mask between a pair of crimp gears. It has been found that crimp gears having a 96 pitch and a 5/8 inch pitch diameter are quite satisfactory. The gears are made about .0005 inch larger in diameter at the center than at the ends to keep the paper from Wandering from side to side. The gears are clamped tightly together, and the paper is wrapped half way around one gear before passing through the bite of the gears to keep the paper from wandering and folding over upon itself. After crimping, the paper has about 28 waves per inch, each about .0035 inch high, the total thickness being about .006 inch. These crimps preferably have the axes of the crimp waves extending perpendicularly to the length of the mask so that these axes will be substantially parallel to the axis of the roll to be formed of the composite mask and image-carrying layer. 'I'he crimped mask is then secured to the treated surface of the image-carrying layer by heat-sealing thereto. complished in a. platen press which applies a uniform pressure simultaneously to a relatively large area, such as several square inches, including a large number of crimps. One preferred press applies a pressure of about 100 pounds per square inch over an area of about square inches for about 1/2 second at a platen surface temperature of approximately 225 F. Due to this large area of application of pressure, the mask cannot ex- This heat-sealing is preferably ac pand appreciably while being sealed to the image-1 carrying layer and it thus remains in its shortenedv condition. Measurements indicate that the sealing pressure lengthens the mask about .5 thereby leaving the mask shortened by about 1.5% from its original length. The sealing pressure, however, mashes the crimps substantially at so that only slight creases remain in the surface of the mask. This mashed crimped mask is shown as being completely flat in the left-hand side of Fig. 2. It is desirable that, at least along the longitudinal edges of the image area portion I8, the mask be substantially fiat at its surface so that there will be no` inequalities of thickness in the layer of liquid spread between the photosensitive layer and the surface of the image area portion I8.

On the right-hand side of Fig. 2' the mask-is shown in its unmashed, crimped form. This portion of the mask adjacent the tear-out hole.

34 is preferably left unsecured to the imagecarrying layer. This portion is indicated by the dotted line 35 in Figure 1 and serves to assist in removal of the image area portion I8 after' the positive has formed on the treated surface thereof. The two sides of Fig. 2 give an excellent comparison between the condition of the mask after crimping but prior to lamination, and; the mask after lamination to the image-carrying.l

layer. When a platen press having a pressure of pounds per square inch is used for sealing the crimped mask to the image-carrying layer, theA deviations in the mask surface have been found to be so slight that they have no visibleeffect upon the thickness of the liquid spread between the photosensitive and image-carrying layers during the processing thereof.

In the use of the above described invention,

the photosensitive emulsion II of the photosensitive layer I0 is suitably exposed in the camera, the two layers IIJ, I2, constituting thev preferred product of the invention, being preferably connected together at their ends and suitably disposed within the camera so that they may be advanced past a processing means'in thel camera with the exposed area of the photosensitive layer in coincident superposed relation to the positive image area 'I8 of the image-carrying layer. In a preferred type of camera the processing means comprises a pair of pressure rolls indicated at 40 in Fig. 1. As the 'two layers pass between these rolls, the container 22 is positoned therebetween and the liquid 2I` is' forcedz from the container mouth 24 by the increased hydraulic pressure created by the rolls 40,'one of which preferably has a pair of spacing collars 42 thereon. Continued movement of the two.-

it being seen that the thickness of the spread' layer of liquid 2| adjacent area I8 is slightlygreater than the total thickness of the com' posite mask I4 due to the presence of collars 42. Liquid spread beyond the end of area I8 is trapped, due to the separation of the pressure rolls, with consequent decrease in hydraulic pres-` sure on the liquid, by the trappingA members 23.; Motion of the product is then-preferably stopped.

The thickness of the layer of liquid spreadforations 20. Since the :mask I4 is unsecured to the image-carrying layer I2 in the neighborhood of hole 34, the stripping of the :image-carry ing `layer from the mask .is facilitated. .es can be .seen .from Fig. .3, -that portion of the sealing layer 32 on Vthe image .area I8 is stripped :away from its adjacent sealing layer 3l). The portionr of sealing layer 32 adhering to image area I8 thus forms a border for the positiveimage formed in or under layer 2| of the processing liquid. It should also be noted that the portions of liquid 2| spread between the mask .I4 and the photosensitive .layer are Atrapped between the mask and photosensitive layer when image area I8 is removed.

It should be pointed out, .in connection with the diagrammatic representation of Fig. .3, that the layer of spread liquid quickly `dries out, during and after the processing, 'to form a Alm of about .0002 inch thick. Thus, when the `time occurs for the image area I8 to be torn out, the film 2l .formed by the spread liquid is considerably `thinner than shown, Yalthough it .is usually not completely dry within a minute of spreading. The flatter portion of the drying is accomplished byvevaporation of the water from the surface thereof exposed as aresult of removal of .area i8.

.It should be yemphasized that the present invention has the important characteristic of permitting the use of a vrelatively weak bond between the .two layers of plastic that seal `the mask to the image-carrying layer. This permits, among other things, the use of organic-solvent-soluble plastics lfor forming both of these sealing layers, thereby preventing wrinkles .in theV mask paper during coating wide sheets thereof and .speedingk the drying operations. These attributes are of considerable importance Where large quantities of Vthese masks must lbe manufactured.

vThetable below 'shows a mask sheet formedof` the materials and in the manner `described `in the example and indicates the degree of stretch of this mask sheet before crimping, the .stretchability of the crimped mask sheet, and the stretchability .of the crimped mask `sheet after it has been .heat sealed. The stretchability of the mask sheet after heat .sealing was 'tested with the .mask sheet `detached from `the imagecarrying layer.

When a mask, having a `stretch characteristic like tha-tof'C in the table, issubjectedftoastress, due Vto unrolllng 'of a composite prod-uct which,

for examplahas been ystored for a long time, any stress tending to separate the mask from they image-.carrying layer is dissipated by .the stretch of themask before this stress can become sufficiently high to cause any shearing of the mask seal.

While a preferred type of mask and process of manufacture thereof have lbeen ldescribed above, it should be understood that considerable lattitudeis feasible Without departing from the scope of the invention. For example, the mask may be crimped by using embossing rolls rather than crimp gears. Additionally, while it is preferable to form the cutaway portions or apertures IB in the mask I4 after .the coating and crimping operations, this step .may be` accomplished at :an earlier stage of the process of manufacture of the product. Equally, variations in the 'strippable adhesive bond may be employed, such, 'for example, as the use of a single .layer .of plastic, the presentinvention permitting lower .strength bonds than previously considered practicable.

Since certain changes may be made in the above product Without departing fromy the .scope of the invention herein involved, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and .not in a limiting sense.

What is claimed is:

l. An elongated composite vsheetlike photographic product, rollable into a roll, and :providing an image-receptive material employable in a photographic transfer vprocess of the character wherein positive image-forming components formed ina photosenstive .layer upon development of a negative latent image therein vare transferred to said image-receptive material for providing a .positive image, said product comprising an elongated flexible image-receiving 'sheet as image-receptive material for receivingsa plurality of positive images by transfer, an @elongated mask sheet of flexible :material superposed on said image-receiving sheet, with the surfaces yof said mask sheet which arein superposed relation to said image-receiving sheet lying 'generally parallel to the image-receiving sheet,l and said mask Vsheet being `crimped and having a Isuccession of waves extending .lengthwise thereof with the respective crests and troughs .of said waves extending transversely of said mask sheet and of said image-receiving sheet whereby the crimped mask sheet is extensible lengthwise vof itself from said crimpedcondition to afully outstretched condition, saidfm'ask sheet lbeing provided with .a plurality of apertures located at spaced intervals in .a direction lengthwise of said mask sheet, each said aperture being adapted to dene a picturearea on saidimage-receiving sheet for receiving a positive transfer image and each :said aperture being of relatively `large area and having a transverse dimension slightly less than the width of k.the :mask sheet so .that the portions of the mask .sheet which bound said aperture in a ldirection longitudinally of said mask sheet are relatively narrow and of small Width in comparison to the width of the mask sheet itself, the .dimensions of each said aperture in ka direction parallel to the longitudinal axis ofthe mask 'sheet being'many times the `distance from crest to crest of .said crmps, a dry stripping adhesive bond interposed between said `mask sheet `and said image-receiving sheet fin superposed relation `and :being substantially :restricted to the -area of :contact between the ncrimizls'fandI the surface of said image-receiving sheet, said mask sheet being secured on said image-receiving sheet in a condition wherein the crimps of the mask sheet are sufficiently attened to impart to the mask sheet, and in a direction longitudinally thereof, a predetermined length which is less than the length of the mask sheet when fully outstretched.

2. An elongated composite sheetlike photosensitive product as defined in claim 1 wherein each aperture in said mask sheet is of a quadrilateral shape.

References Cited in the iile of this patent UNITED STATES PATENTS Number Name Date 626,356 Whitney June 6, 1899 763,024 Schmid June 21, '1904 856,783 Ketchum June 11, 1907 1,232,796 Hardenbrook July 10, 1917 1,250,099 Davis Dec. 11, 1917 1,360,142 OBrien Nov. 23, 1920 1,467,543 Hansen Sept. 11, 1923 1,588,869 Wolk June 15, 1926 1,751,882 Pifer Mar. 25, 1930 1,823,278 Martin Sept. 15, 1931 1,902,312 Rous Mar. 21, 1933 Number Number 10 Name Date Thornton Oct. 10, 1933 Hagedorn Aug. 6, 1935 Lane Dec. 29, 1936 Wittel Jan. 11, 1938 Nadeau Jan. 10, 1939 Rowe June 6, 1939 Bruker et al. Oct. 22, 1940 Schwartz July 29, 1941 Nadeau Dec. 16, 1941 Coulter Aug. 31, 1943 Rabkin June 20, 1944 White Nov. 28, 1944 Ray Feb. 27, 1945 Rhodes Mar. 13, 1945 Muskat June 26, 1945 Staud Apr. 9, 1946 Heinecke Oct. 15, 1946 Blessing July 15, 1947 Morrison July 15, 1947 Moore Aug. 5, 1947 Ives Apr. 11, 1950 FOREIGN PATENTS Country Date Switzerland Feb. 1, 1904 France May 6, 1922 

1. AN ELONGATED COMPOSITE SHEETLIKE PHOTOGRAPHIC PRODUCT, ROLLABLE INTO A ROLL, AND PROVIDING AN IMAGE-RECEPTIVE MATERIAL EMPLOYABLE IN A PHOTOGRAPHIC TRANSFER PROCESS OF THE CHARACTER WHEREIN POSITIVE IMAGE-FORMING COMPONENTS FORMED IN A PHOTOSENSITIVE LAYER UPON DEVELOPMENT OF A NEGATIVE LATENT IMAGE THEREIN ARE TRANSFERRED TO SAID IMAGE-RECEPTIVE MATERIAL FOR PROVIDING A POSITIVE IMAGE, SAID PRODUCT COMPRISING AN ELONGATED FLEXIBEL IMAGE-RECEIVING SHEET AS IMAGE-RESPECTIVE MATERIAL FOR RECEIVING A PLURALITY OF POSITIVE IMAGES BY TRANSFER, AN ELONGATED MASK SHEET OF FLEXIBLE MATERIAL SUPERPOSED ON SAID IMAGE-RECEIVING SHEET, WITH THE SURFACES OF SAID MASK SHEET WHICH ARE IN SUPERPOSED RELATION TO SAID IMAGE-RECEIVING SHEET LYING GENERALLY PARALLEL TO THE IMAGE-RECEIVING SHEET, AND SAID MASK SHEET BEING CRIMPED AND HAVING A SUCCESSION OF WAVES EXTENDING LENGTHWISE THEREOF WITH THE RESPECTIVE CRESTS AND TROUGHS OF SAID WAVES EXTENDING TRANSVERSELY OF SAID MASK SHEET AND OF SAID IMAGE-RECEIVING SHEET WHEREBY THE CRIMPED MASK SHEET IS EXTENSIBLE LENGTHWISE OF ITSELF FROM SAID CRIMPED CONDITION TO A FULLY OUTSTRETCHED CONDITION, SAID MASK SHEET BEING PROVIDED WITH A PLURALITY OF APERTURES LOCATED AT SPACED INTERVALS IN A DIRECTION LENGTHWISE OF SAID MASK SHEET, EACH SAID APERTURE BEING ADAPTED TO DEFINE A PICTURE AREA ON SAID IMAGE-RECEIVING SHEET FOR RECEIVING A POSITIVE TRANSFER IMAGE AND EACH SAID APERTURE BEING OF RELATIVELY LARGE AREA AND HAVING A TRANSVERSE DIMENSION SLIGHTLY LESS THAN THE WIDTH OF THE MASK SHEET SO THAT THE PORTIONS OF THE MASK SHEET WHICH BOUND SAID APERTURE IN A DIRECTION LONGITUDINALLY OF SAID MASK SHEET ARE RELATIVELY NARROW AND OF SMALL WIDTH IN COMPARISON TO THE WIDTH OF THE MASK SHEET ITSELF, THE DIMENSIONS OF EACH SAID APERTURE IN A DIRECTION PARALLEL TO THE LONGITUDINAL AXIS OF THE MASK SHEET BEING MANY TIMES THE DISTANCE FROM CREST TO CREST OF SAID CRIMPS, A DRY STRIPPING ADHESIVE BOND INTERPOSED BETWEEN SAID MASK SHEET AND SAID IMAGE-RECEIVING SHEET IN SUPERPOSED RELATION AND BEING SUBSTANTIALLY RESTRICTED TO THE AREA OF CONTACT BETWEEN THE CRIMPS AND THE SURFACE OF SAID IMAGE-RECEIVING SHEET, SAID MASK SHEET BEING SECURED ON SAID IMAGE-RECEIVING SHEET IN A CONDITION WHEREIN THE CRIMPS OF THE MASK SHEET ARE SUFFICIENTLY FLATTENED TO IMPART TO THE MASK SHEET, AND IN A DIRECTION LONGITUDINALLY THEREOF, A PREDETERMINED LENGTH WHICH IS LESS THAN THE LENGTH OF THE MASK SHEET WHEN FULLY OUTSTRETCHED. 